Synthesis of trans-Mono(silyl)palladium(II) Bromide Complexes

The stoichiometric reaction of cis-[Pd(ITMe)₂(SiR₃)₂], where (SiR₃ = SiMe₃ and SiMe₂Ph and ITMe = 1,3,4,5-tetramethylimidazol-2-ylidene) with allyl bromide affords the corresponding allylsilanes along with complexes of the type trans-[Pd(ITMe)₂(SiR₃)(Br)]. The structure of trans-[Pd(ITMe)₂(SiMe₂Ph)Br] 2b has been determined in the solid state and displays a slightly distorted square-planar geometry with the two N-heterocyclic carbene ligands in a trans-configuration.     

Synthesen und Strukturen von Bis(4,4′‐t‐butyl‐2,2′‐bipyridin)‐Ruthenium(II)‐Komplexen mit funktionellen Derivaten des Tetramethyl‐bibenzimidazols

Syntheses and Structures of Bis(4,4′‐t‐butyl‐2,2′‐bipyridine) Ruthenium(II) Complexes with functional Derivatives of Tetramethyl‐bibenzimidazole [(tbbpy)₂RuCl₂] reacts with dinitro‐tetramethylbibenzimidazole ( A ) in DMF to form the complex [(tbbpy)₂Ru( A )](PF₆)₂ ( 1a ) (tbbpy: bis(4,4′‐t‐butyl)‐2,2′bipyridine). Exchange of the two PF₆^? anions by a mixture of tetrafluor‐terephthalat/tetrafluor‐terephthalic acid results in the formation of 1b in which an extended hydrogen‐bonded network is formed. According to the ¹H NMR spectra and X‐ray analyses of both 1a and 1b , the two nitro groups of the bibenzimidazole ligand are situated at the periphery of the complex in cis position to each other. Reduction of the nitro groups in 1a with SnCl₂/HCl results in the corresponding diamino complex 2 which is a useful starting product for further functionalization reactions. Substitution of the two amino groups in 2 by bromide or iodide via Sandmeyer reaction results in the crystalline complexes [(tbbpy)₂Ru( C )](PF₆)₂ and [(tbbpy)₂Ru( D )](PF₆)₂ ( C : dibromo‐tetrabibenzimidazole, D : diiodo‐tetrabibenzimidazole). Furthermore, 2 readily reacts with 4‐t‐butyl‐salicylaldehyde or pyridine‐2‐carbaldehyde under formation of the corresponding Schiff base Ru^II complexes 5 and 6 . ¹H NMR spectra show that the substituents (NH₂, Br, I, azomethines) in 2 ‐ 6 are also situated in peripheral positions, cis to each other. The solid state structure of both 2 , and 3 , determined by X‐ray analyses confirm this structure. In addition, the X‐ray diffraction analyses of single crystals of the complexes [(tri‐t‐butyl‐terpy)(Cl)Ru( A )] ( 7 ) and [( A )PtCl₂] ( 8 ) display also that the nitro groups in these complexes are in a cis‐arrangement.     

Novel Octahedral Bis[2‐(1‐aziridinyl)ethanol‐κ2N,O] Complexes of Cobalt(II)

The synthesis and molecular structure of trans‐{bis[(acetato‐κO)‐(2‐(1‐aziridinyl)ethanol‐κ²N,O)]}cobalt(II) ( 4 ) and cis‐{bis[chlorido‐(2‐(1‐aziridinyl)ethanol‐κ²N,O)]}cobalt(II) ( 5 ) is reported. Both neutral chelate complexes are prepared from the corresponding Co^II salt [CoX₂; X = OAc ( 1 ), Cl ( 2 )] and 2‐(1‐aziridinyl)ethanol (azolH, 3 ) in dry dichloromethane. A third, ionic complex, cis‐{bis[aqua‐(2‐(1‐aziridinyl)ethanol‐κ²N,O)]}cobalt(II) diacetate ( 6 ) is formed from 4 in the presence of water and could be crystallized from aqueous dichloromethane. In all cases, 2‐(1‐aziridinyl)ethanol is coordinating as bidentate chelate ligand by the nitrogen and oxygen atom of the aziridinyl and hydroxy moiety. After purification, the compounds have been fully characterized using IR spectroscopy and FAB⁺‐MS. The single‐crystal X‐ray structure analysis revealed a distorted octahedral geometry for all complexes with either trans ( 4 ) or cis ( 5 , 6 ) configuration.     

2,3‐Di(2‐pyridyl)‐5‐phenylpyrazine: A NN‐CNN‐Type Bridging Ligand for Dinuclear Transition‐Metal Complexes

A new bridging ligand, 2,3‐di(2‐pyridyl)‐5‐phenylpyrazine (dpppzH), has been synthesized. This ligand was designed so that it could bind two metals through a NN‐CNN‐type coordination mode. The reaction of dpppzH with cis‐[(bpy)₂RuCl₂] (bpy=2,2′‐bipyridine) affords monoruthenium complex [(bpy)₂Ru(dpppzH)]²⁺ ( 12+ ) in 64 % yield, in which dpppzH behaves as a NN bidentate ligand. The asymmetric biruthenium complex [(bpy)₂Ru(dpppz)Ru(Mebip)]³⁺ ( 23+ ) was prepared from complex 12+ and [(Mebip)RuCl₃] (Mebip=bis(N‐methylbenzimidazolyl)pyridine), in which one hydrogen atom on the phenyl ring of dpppzH is lost and the bridging ligand binds to the second ruthenium atom in a CNN tridentate fashion. In addition, the RuPt heterobimetallic complex [(bpy)₂Ru(dpppz)Pt(C?CPh)]²⁺ ( 42+ ) has been prepared from complex 12+ , in which the bridging ligand binds to the platinum atom through a CNN binding mode. The electronic properties of these complexes have been probed by using electrochemical and spectroscopic techniques and studied by theoretical calculations. Complex 12+ is emissive at room temperature, with an emission λ_max=695 nm. No emission was detected for complex 23+ at room temperature in MeCN, whereas complex 42+ displayed an emission at about 750 nm. The emission properties of these complexes are compared to those of previously reported Ru and RuPt bimetallic complexes with a related ligand, 2,3‐di(2‐pyridyl)‐5,6‐diphenylpyrazine.     

Reactions of tBu2P–PLi–PtBu2 with [(Et3P)2MCl2] (M = Ni,Pd, Pt). Synthesis and Properties of [(1,2‐η‐tBu2P=P–PtBu2)M(PEt3)Cl] (M=Ni,Pd)

^tBu₂P–PLi–P^tBu₂·2THF reacts with [cis‐(Et₃P)₂MCl₂] (M = Ni, Pd) yielding [(1,2‐η‐^tBu₂P=P–P^tBu₂)Ni(PEt₃)Cl] and [(1,2‐η‐^tBu₂P=P–P^tBu2)Pd(PEt₃)Cl], respectively. ^tBu₂P– PLi–P^tBu₂ undergoes an oxidation process and the ^tBu₂P–P–P^tBu₂ ligand adopts in the products the structure of a side‐on bonded 1,1‐di‐tert‐butyl‐2‐(di‐tert‐butylphosphino)diphosphenium cation with a short P–P bond. Surprisingly, the reaction of ^tBu₂P–PLi–P^tBu₂·2THF with [cis‐(Et₃P)₂PtCl₂] does not yield [(1,2‐η‐^tBu₂P=P–P^tBu₂)Pt(PEt₃)Cl].     

Bis(amido)cyclodiphosph(III)azane Complexes of Yttrium and the Lanthanides

The first cyclodiphosph(III)azane complexes of the rare‐earth elements have been synthesized. Reactions of the lithium salt cis‐[(tBuNP)₂(tBuN)₂{Li(thf)}₂] with anhydrous yttrium trichloride or the heavier lanthanide trichlorides resulted in the corresponding cyclodiphosph(III)azane complexes [Li(thf)₄][{(tBuNP)₂(tBuN)₂}LnCl₂] (Ln=Y ( 1 a ), Ho ( 1 b ), Er ( 1 c )). The single‐crystal X‐ray structures showed that compounds 1 a – c consisted of ion pairs composed of a [Li(thf)₄]⁺ cation and a C_2v symmetric [{(tBuNP)₂(tBuN)₂}LnCl₂]^? anion. By treating cis‐[(tBuNP)₂(tBuN)₂{Li(thf)}₂] with anhydrous SmCl₃ in THF, the trimetallic complex [{(tBuNP)₂(tBuN)₂}SmCl₃Li₂(thf)₄] ( 2 ) was obtained. The influence of the ionic radii of the lanthanides can be seen in the single‐crystal X‐ray structure of compound 2 , which forms a six‐membered Cl‐Li‐Cl‐Li‐Cl‐Sm metallacycle. The ring adopts a boat conformation in which one chlorine atom and the samarium atom are displaced from the Cl₂Li₂ least‐square plane. Heating of the metalate complexes in toluene resulted in the extrusion of lithium chloride and the formation of the neutral dimeric metal chloride complexes of the composition [(tBuNP)₂(tBuN)₂LnCl(thf)]₂ (Ln=Y ( 3 a ), La ( 3 b ) Nd ( 3 c ), Sm ( 3 d )). Furthermore, treating 1 a with KNPh₂ resulted in a lithium metalate complex of the composition [Li(thf)₄][{(tBuNP)₂(tBuN)₂}Y(NPh₂)₂] ( 4 ). The coordination mode of the {(tBuNP)₂(tBuN)₂}^2? ligand in 4 is different to that observed in 1 a – c , 2 , and 3 a – d ; instead of a symmetric η² coordination of the ligand, a heterocubane‐type structure is observed in the solid state. The complex [(tBuNP)₂(tBuN)₂NdCl(thf)] ( 3 c ) was used as a Ziegler–Natta catalyst for the polymerization of 1,3‐butadiene to poly‐cis‐1,4‐butadiene. The observed activities of the Ziegler–Natta catalyst strongly depended upon the nature of the cocatalyst; in some case very high turnover rates and a cis selectivity of 93–94 % were observed.     

Die Kristallstruktur von cis‐ und trans‐N‐iso‐Propylamidodimethylindium, [(CH3)2In‐N(H)iC3H7]2

The Crystal Structure of cis‐ and trans‐N‐iso‐Propylamidodimethyl Indium, [(CH₃)₂In‐N(H)ⁱC₃H₇]₂ According to the X‐ray structure determination [(CH₃)₂In‐N(H)ⁱC₃H₇]₂ (prepared from InMe₃ (Me = CH₃) and H₂NⁱPr (ⁱPr = CH(CH₃)₂) crystallizes in the monoclinic space group P2₁/n with 3 dimeric trans as well as 3 dimeric cis isomers per unit cell. The centrosymmetric form has a planar In₂N₂ core with In—N bonds of 222.1(4) and 222.9(5) pm, respectively, the skeleton of the cis isomer with In—N bonds of 221.4(4) pm is slightly folded (13.7°). Some ¹H, ¹³C NMR, IR, and Raman data are reported.     

Preparation and Characterization of Dinuclear Chromium(III) Complexes of a Hexadentate Tetraaza‐Dithiophenolate Ligand

The ability of the tetraaza‐dithiophenolate ligand H₂L² (H₂L² = N,N′‐Bis‐[2‐thio‐3‐aminomethyl‐5‐tert‐butyl‐benzyl]propane‐1,3‐diamine) to form dinuclear chromium(III) complexes has been examined. Reaction of Cr^IICl₂ with H₂L² in methanol in the presence of base followed by air‐oxidation afforded cis,cis‐[(L²)Cr^III₂(μ‐OH)(Cl)₂]⁺ ( 1a ) and trans,trans‐[(L²)Cr^III₂(μ‐OH)(Cl)₂]⁺ ( 1b ). Both compounds contain a confacial bioctahedral N₂ClCr^III(μ‐SR)₂(μ‐OH)Cr^IIIClN₂ core. The isomers differ in the mutual orientation of the coligands and the conformation of the supporting ligand. In 1a both Cl^? ligands are cis to the bridging OH function. In 1b they are in trans‐positions. Reaction of the hydroxo‐bridged complexes with HCl yielded the chloro‐bridged cations cis,cis‐[(L²)Cr^III₂(μ‐Cl)(Cl)₂]⁺ ( 2a ) and trans,trans‐[(L²)Cr^III₂(μ‐Cl)(Cl)₂]Cl ( 2b ), respectively. These bridge substitutions proceed with retention of the structures of the parent complexes 1a and 1b .     

Metal Derivatives of Heterocyclic‐2‐thiones: Crystal Structures of [Bis(diphenylphosphanyl)propane][bis(pyrimidine‐2‐thiolato)]ruthenium(II) and [Bis(diphenylphosphanyl)methane][bis(pyridine‐2‐thiolato)]ruthenium(II)

Ruthenium(II) Complexes containing pyrimidine‐2‐thiolate (pymS^–) and bis(diphenylphosphanyl)alkanes [Ph₂P–(CH₂)_m–PPh₂, m = 1, dppm; m = 2, dppe; m = 3, dppp; m = 4, dppb] are described. Reactions of [RuCl₂L₂] (L = dppm, dppp) and [Ru₂Cl₄L₃] (L = dppb) with pyrimidine‐2‐thione (pymSH) in 1:2 molar ratio in dry benzene in the presence of Et₃N base yielded the [Ru(pymS)₂L] complexes (pymS^– = pyrimidine‐2‐thiolate; L = dppm ( 1 ); dppp ( 3 ); dppb ( 4 )). The complex [Ru(pymS)₂(dppe)] ( 2 ) was indirectly prepared by the reaction of [Ru(pymS)₂(PPh₃)₂] with dppe. These complexes were characterized using analytical data, IR, ¹H, ¹³C, ³¹P NMR spectroscopy, and X‐ray crystallography (complex 3 ). The crystal structure of the analogous complex [Ru(pyS)₂(dppm)] ( 5 ) with the ligand pyridine‐2‐thiolate (pyS^–) was also described. X‐ray crystallographic investigation of complex 3 has shown two four‐membered chelate rings (N, S donors) and one six‐membered ring (P, P donors) around the metal atom. Compound 5 provides the first example in which Ru^II has three four‐membered chelate rings: two made up by N, S donor ligands and one made up by P, P donor ligand. The arrangement around the metal atoms in each complex is distorted octahedral with cis:cis:trans:P, P:N, N:S, S dispositions of the donor atoms. The ³¹P NMR spectroscopic data revealed that the complexes are static in solution, except 2 , which showed the presence of more than one species.     

N,N, N′, N′‐Tetrakis(diphenylphosphanyl)‐1, 3‐diaminobenzene as a Bis‐chelate Ligand in [1, 3‐{cis‐Mo(CO)4(PPh2)2N}2C6H4]

1, 3‐Diaminobenzene reacts readily with PPh₂Cl to give N, N, N′, N′‐tetrakis(diphenylphosphanyl)‐1, 3‐diaminobenzene ( 1 ) in excellent yield. The dinuclear complex [1, 3‐{cis‐Mo(CO)₄(PPh₂)₂N}₂C₆H₄] ( 2 ) is obtained in high yield from 1 and cis‐[Mo(CO)₄(NCEt)₂]. Compounds 1 and 2 were characterized by NMR spectroscopy (¹H, ¹³C, ³¹P) and by crystal structure determination. The latter shows the formation of a bis‐chelate complex with Mo‐P‐N‐P four‐membered rings.     

A new [(1R,2R)‐1,2‐diaminocyclohexane]platinum(II) complex: formation by nitrate–acetonitrile ligand exchange

The title compound, cis‐diacetonitrile[(1R,2R)‐1,2‐diaminocyclohexane‐κ²N,N′]platinum(II) dinitrate monohydrate, [Pt(C₂H₃N)₂(C₆H₁₄N₂)](NO₃)₂·H₂O, is a molecular salt of the diaminocyclohexane–Pt complex cation. There are two formula units in the asymmetric unit. Apart from the two charge‐balancing nitrate anions, one neutral molecule of water is present. The components interact via N—H...O and O—H...O hydrogen bonds, resulting in supramolecular chains. The title compound crystallizes only from acetonitrile with residual water, with the acetonitrile coordinating to the molecule of cis‐[Pt(NO₃)₂(DACH)] (DACH is 1,2‐diaminocyclohexane) and the water forming a monohydrate.     

(NH4)3[VO2(SO4)2(H2O)2]·1.5H2O

The title compound, tri­ammonium cis‐di­aqua‐cis‐dioxo‐trans‐disulfatovanadate 1.5‐hydrate, was obtained by oxidizing V^IV to V^V in a 2 M sulfuric acid solution of vanadyl­ sulfate and adding ammonium sulfate. Here, the V atom is sandwiched by two sulfate groups by corner‐sharing to form a discrete [VO₂(SO₄)₂(OH₂)₂]^3? anion. The water mol­ecules occupy cis positions in the equatorial plane of the vanadium octahedron.     

Komplexe mit Antimon‐Liganden: [tBu2(Cl)SbW(CO)5], [tBu2(OH)SbW(CO)5], O[SbPh2W(CO)5]2, E[SbMe2W(CO)5]2 (E = Se,Te), cis‐[(Me2SbSeSbMe2)2Cr(CO)4]

Complexes Containing Antimony Ligands: [^tBu₂(Cl)SbW(CO)₅], [^tBu₂(OH)SbW(CO)₅], O[SbPh₂W(CO)₅]₂, E[SbMe₂W(CO)₅]₂ (E = Se, Te), cis‐[(Me₂SbSeSbMe₂)₂Cr(CO)₄] Syntheses of [^tBu₂(Cl)SbW(CO)₅] ( 1 ), [^tBu₂(OH)SbW(CO)₅] ( 2 ), O[SbPh₂W(CO)₅]₂ ( 3 ), Se[SbMe₂W(CO)₅]₂ ( 4 ), cis‐[(Me₂SbSeSbMe₂)₂Cr(CO)₄] ( 5 ) Te[SbMe₂W(CO)₅]₂ ( 6 ) and crystal structures of 1 – 5 are reported.     

Reaction of dimethylplatinum(II) complexes with PhCH2CH2Br: Comparative reactivity with CH3CH2Br and PhCH2Br and synthesis of Pt(IV) complexes

Oxidative addition of 2‐phenylethylbromide (PhCH₂CH₂Br) to dimethylplatinum(II) complexes [PtMe₂(NN)] ( 1a , NN = 2,2′‐bipyridine (bpy); 1b , NN = 1,10‐phenanthroline (phen)) afforded the new organoplatinum(IV) complexes [PtMe₂(Br)(PhCH₂CH₂)(bpy)], as a mixture of trans ( 2a ) and cis ( 3a ) isomers, and [PtMe₂(Br)(PhCH₂CH₂)(phen)], as a mixture of trans ( 2b ) and cis ( 3b ) isomers, respectively. The new Pt(IV) complexes were readily characterized using multinuclear (¹H and ¹³C) NMR spectroscopy and elemental microanalysis. The crystal structure of 2a was further determined using X‐ray crystallography indicating an octahedral geometry around the platinum centre. A comparison of reactivity of RCH₂Br reagents (R = CH₃, Ph or PhCH₂) in their oxidative addition reactions with complex 1a , with an emphasis on the effects of the R groups of alkyl halides, was also conducted using density functional theory.     

2H‐Azirines as Ligands: Structural Characterization of the First Neutral and Cationic (η5‐C5Me5)Rh(III) 2H‐Azirine Complexes

The synthesis and structural characterization of two azirine rhodium(III ) complexes are described. The stabilization, N‐coordination and phenylgroup π‐stacking of the highly reactive and strained 3‐phenyl‐2H‐azirine by transition metal coordination is observed. The reaction of the dimeric complex [(η⁵‐C₅Me₅)RhCl₂]₂ with 3‐phenyl‐2H‐azirine (az) in CH₂Cl₂ at room temperature in a 1:2 molar ratio afforded the neutral mono‐azirine complex [(η⁵‐C₅Me₅)RhCl₂(az)]. The subsequent reaction of [(η⁵‐C₅Me₅)RhCl₂]₂ with six equivalents of az and 4 equivalents of AgOTf yielded the cationic tris‐azirine complex [(η⁵‐C₅Me₅)Rh(az)₃](OTf)₂. After purification, all complexes have been fully characterized. The molecular structures of the novel rhodium(III ) complexes exhibit slightly distorted octahedral coordination geometries around the metal atoms.     

Synthesis and Structure of the Cerium Schiff‐Base Complexes [Ce(Salen′)2] and [(THF)2KCe(Salen′)2]

The synthesis of [Ce(Salen′)₂] ( 1 ) (H₂Salen′ = N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)ethylenediamine) was performed using two different approaches. CeCl₃ reacts with two equivalents of K₂Salen′ in THF under the formation of [(THF)₂KCe(Salen′)₂] ( 2 ). Complex 2 could be converted to the Ce^IV complex 1 via oxidation with p‐benzoquinone and air, respectively. The reversible reduction process was realized using elemental potassium in boiling THF. Furthermore, the reaction of the Ce^IV starting material [(^tBuO)₄Ce(THF)₂] with the “free” ligand H₂Salen′ in boiling toluene lead in the formation of 1 as well.     

A Dissociative Route to C?H Bond Activation: Ligand Cyclometalation in cis‐Dimethyl[(sulfinyl‐κS)bis[methane]][tris(2‐methylphenyl)phosphine]platinum(2+)

The dialkyl compound cis‐dimethyl[(sulfinyl‐κS)bis[methane]][tris(2‐methylphenyl)phosphine]platinum(2+) (cis‐[Pt(Me)₂(dmso)(P(o‐tol)₃]; 1 ) has been isolated from the reaction of cis‐dimethylbis[(sulfinyl‐κS)bis[methane]]platinum(2+) (cis‐[Pt(Me)₂(dmso)₂]) with tris(2‐methylphenyl)phosphane (P(o‐tol)₃). Restricted rotation around the P? C_ipso bonds of the phosphane ligand generates two different conformers, 1a and 1b , in rapid exchange in non‐polar solvents at low temperature. Strong through‐space contacts between the ortho‐Me substituent groups on the ligand and the cis‐Me groups in the coordination plane were determined, which proved useful for identifying the atropisomers formed. At room temperature, ¹H‐NMR spectra of 1 maintain a ‘static’ pattern upon onset of easy and rapid ortho‐platination, leading to [[2‐[bis(2‐methylphenyl)phosphino‐κP]phenyl]methyl‐κC]methyl[(sulfinyl‐κS)bis[methane]]platinum(2+) ( 2 ), a new C,P‐cyclometalated compound of platinum(II), with liberation of methane. The process has been studied by ¹H‐ and ³¹P{¹H}‐NMR in CDCl₃, and kinetics experiments were performed by conventional spectrophotometric techniques. The first‐order rate constants k_c decrease with the addition of dimethyl sulfoxide until the process is blocked by the presence of a sufficient excess of sulfoxide. This behavior reveals a mechanism initiated by ligand dissociation and formation of a three‐coordinate species. The value of the rate constant for dimethyl sulfoxide dissociation k₁ has been measured independently over a wide temperature range by both ¹H‐NMR ligand exchange (isotopic labeling experiments) and ligand substitution (stopped‐flow pyridine for dimethyl sulfoxide substitution). The rates of the two processes are in reasonable agreement at the same temperature, and a single Eyring plot can be constructed with the two sets of kinetics data. However, the value of the derived dissociation constant at 308 K (k₁=6.5±0.3 s^?1) is at least two orders of magnitude higher than that of cyclometalation (k_c=0.0098±0.0009 s^?1 at 308 K). Clearly, the dissociation step is not rate‐determining for cyclometalation. A multistep mechanism consistent with mass‐law retardation is derived, which involves a pre‐equilibrium that controls the concentration of an unsaturated three‐coordinate, 14‐electron T‐shaped cis‐[PtMe₂{P(o‐tol)₃}] intermediate. Cyclometalation is initiated in this latter by an agostic interaction with the σ(C? H) orbital of a methyl group. Oxidative addition of the C? H bond follows, yielding a cyclometalated‐hydrido 16‐electron Pt(IV) five‐coordinate intermediate. Finally, reductive elimination and re‐entry of dimethyl sulfoxide with liberation of methane should yield the cyclometalated species 2 .     

一种新型顺式异三核金属[Cu-Mn-Cu]配合物合成、晶体结构和磁性

合成了一种新型不对称Schiff碱铜前体配合物KCuL和一种化学组成为[(CuL)2Mn (H2O)2]·0.5CH3OH·0.5CH3OH的顺式异三核配合物,并通过元素分析、IR谱的方法对其进行了表征（其中H3L = N-(2-{[(1E)-(5-氯-2-羟基苯基)亚甲基]胺基}乙基)-2-羟基苯甲酰胺）。利用X-射线单晶衍射方法对三核配合物的晶体结构进行了测定。该三核配合物的每一晶胞单元含有一个顺式中性异三核分子和两个无序的甲醇分子。中心锰离子Mn2+处于O6形成的变形八面体几何构型,而两个配阴离子[CuL]-在Mn2+周围呈顺式排布。磁性表明该三核配合物不仅具有分子内反铁磁作用,而且三核单元之间具有弱的铁磁交换作用,磁参数分别为J = -12.1 cm-1, g = 2.20 and zj¢ = 1.37 cm-1.     

Dinuclear complexes with a μ-cyano ligand. Part XI(1). Synthesis and characterization of several derivatives ofcis-[Co(NH3)(en)2(H2O)]3+

Summary The new complex double saltscw-[Co(NH₃)(en)₂(H₂O)]₂ [M(CN)₄]₃ (en = ethylenediamine; M = Ni, Pd or Pt),cis-[Co(NH₃(en)₂(H₂O)]₂[FeNO(CN)₅]₃ andcis-[Co(NH₃)(en)₂(H₂O)][Co(CN)₆] have been synthesized and by anation in the solid state the corresponding new dinuclear complexes with a cyano bridgecis- ortrans-[(NH₃)(en)₂Co-NC-M(CN)₃]₂ [M(CN)₄] (M = Ni, Pd or Pt);cis-, trans-[(NH₃)(en)₂Co-NC-FeNO(CN)₄]₂[FeNO(CN)₅] andcis-[(NH₃)(en)₂Co-NC-Co(CN)₅ have been prepared. The complexes have been characterized by chemical analysis, t.g. measurements, and by i.r. and electronic spectroscopy. With [Ni(CN)₄][^2– and [Co(CN)in]₆ ^3– only thecis-isomer is produced; with [Pd(CN)₄]^2–, [Pt(CN)₄]^2– and [FeNO(CN)₅]^2– thetrans- isomer is the dominant species. The dinuclear complex derived from [Pt(CN)₄]^2– shows strong Pt-Pt interactions both in the solid state and in solution.     

Homogeneous [RuIII(Me3tacn)Cl3]‐Catalyzed Alkene cis‐Dihydroxylation with Aqueous Hydrogen Peroxide

A simple and green method that uses [Ru(Me₃tacn)Cl₃] ( 1 ; Me₃tacn=N,N′,N′′‐trimethyl‐1,4,7‐triazacyclononane) as catalyst, aqueous H₂O₂ as the terminal oxidant, and Al₂O₃ and NaCl as additives is effective in the cis‐dihydroxylation of alkenes in aqueous tert‐butanol. Unfunctionalized alkenes, including cycloalkenes, aliphatic alkenes, and styrenes (14 examples) were selectively oxidized to their corresponding cis‐diols in good to excellent yield (70–96 %) based on substrate conversions of up to 100 %. The preparation of cis‐1,2‐cycloheptanediol (119 g, 91 % yield) and cis‐1,2‐cyclooctanediol (128 g, 92 % yield) from cycloheptene and cyclooctene, respectively, on the 1‐mol scale can be achieved by scaling up the reaction without modification. Results from Hammett correlation studies on the competitive oxidation of para‐substituted styrenes (ρ=?0.97, R=0.988) and the detection of the cycloadduct [(Me₃tacn)ClRuHO₂(C₈H₁₄)]⁺ by ESI‐MS for the 1 ‐catalyzed oxidation of cyclooctene to cis‐1,2‐cyclooctanediol are similar to those of the stoichiometric oxidation of alkenes by cis‐[(Me₃tacn)(CF₃CO₂)Ru^VIO₂]⁺ through [3+2] cycloaddition (W.‐P. Yip, W.‐Y. Yu, N. Zhu, C.‐M. Che, J. Am. Chem. Soc. 2005 , 127, 14239).